Write short note on IPv6

Mumbai university > Electronics and telecommunication Engineering > Sem 6 > Computer Communication and Telecom Network

Marks: 10

Years: May 2016

1. IPv6 is the next generation Internet Protocol designed as a successor to the IP version 4.
2. IPv6 was designed to enable high performance, scalable internet.
3. This was achieved by overcoming many of the weaknesses of IPv4 protocol and by adding several new features.
4. In IPv6, there are 2128 possible ways (about 3.4 x 1038 addresses).
5. IPv6 is written in hexadecimal and consists of 8 groups, containing 4 hexadecimal digits or 8 groups of 16 bits each.
6. The IPv6 header is a static header of 40 bytes in length and has only 8 fields. Option information is carried by the extension header which is placed after the IPv6 header.
7. IPv6 has no header checksum because checksums are for example above the TCP/IP protocol suite and above the Token Ring, Ethernet etc.
8. The IPv6 header contains an 8 bit field called the Traffic Class Field. This field allows the traffic source to identify the desired delivery priority of its packets.
9. The IPv6 has both a stateful and stateless address auto-configuration mechanism.
10. IPv6 has been designed to satisfy the growing and expanded need for network security.
11. Source and destination addresses are 128 bits (16 bytes) in length.
12. Packet flow identification for QoS handling by routers is included in the IPv6 header using the Flow Label Field.
13. ARP request frames are replaced with multicast neighbour solicitation messages.
14. ICMP router discovery is replaced with ICMPv6 router solicitation and router advertisement messages are required.

15. IPv6 has three different types of addresses.

    Unicast: A unicast address defines a single computer. A packet sent to a unicast address is delivered to that specific computer.

    Anycast: This is a type of address that defines a group of computers with addresses which have the same prefix. A packet sent to an anycast address must be delivered to exactly one of the members of the group which is closest or the most easily accessible.

    Multicast: A multicast address defines a group of computers which may or may not share the same prefix and may or may not be connected to the same physical network. A packet sent to a multicast address must be delivered to each member of the set.

16. Advantages of IPv6:

    • Larger address space: IPv6 has 128 bit address space which is 4 times wider in bits compared to IPv4’s 32 bit address space. So there is a huge increase in the address space.

    • Better header format: IPv6 uses a better header format. In its header format the option are separated from the base header. The options are inserted when needed between the base header and upper layer data. This helps in speeding up the routing process.

    • New options: New options have been added in IPv6 to increase the functionality.

    • Possibility of extension: IPv6 has been designed in such a way that there is a possibility of extension of protocol if required.

    • More security: IPv6 includes security in the basic specification. It includes encryption of packets (ESP: Encapsulated Security Protocol) and authentication of the sender of packets (AH: Authentication Header)

    • Support to resource allocation: To implement better support for real time traffic (such as video conference), IPv6 includes flow label in the specification. With flow label mechanism, routers can recognize to which end-to-end flow the packets belongs.

    • Plug and play: IPv6 includes plug and play in the standard specification. It therefore must be easier for novice users to connect their machines to the network, it will be done automatically.

    • Clearer specification and optimization: IPv6 follows good practices of IPv4 and rejects minor flaws/obsolete items of IPv4.